GE-Hitachi completes the first step of ONR’s Generic Design Assessment

The GDA process enables regulators to assess new nuclear power station designs at an early stage of the regulatory process and provide confidence that these new designs can be constructed, operated, and decommissioned in Great Britain.

The assessment is restricted to the design of a generic nuclear power station. It is not site-specific and does not consider any specific arrangements or capabilities of a future developer or operator.

The focus of the regulators during Step 1 has been ensuring the necessary arrangements, processes and submissions are established to commence the Step 2 of GDA, and that an agreed scope and schedule for the technical assessment of the GE-Hitachi BWRX-300 are in place.

Based on the evidence provided, the regulators are satisfied that GE-Hitachi has demonstrated its readiness to proceed to Step 2.

During Step 2, regulatory activity will be targeted on assessing the fundamental adequacy of the GE-Hitachi BWRX-300 design for deployment in Great Britain. 

This will consider the suitability of the methodologies, approaches, codes, standards and philosophies identified by GE-Hitachi in the generic safety, security, safeguards and environment cases for securing future regulatory permissions and permits.

Rob Exley, ONR’s Head of Regulation for the GE-Hitachi BWRX-300 design, said: “Step 2 of the GDA will mark the beginning of ONR’s technical assessment of the BWRX-300 reactor, where we’ll examine GE-Hitachi’s submissions setting out why it believes its generic design can be safely and securely deployed in Great Britain.

“We will also seek to build upon our collaborative partnerships with both the US Nuclear Regulatory Commission and the Canadian Nuclear Safety Commission.

“We are fully supportive of GE-Hitachi’s ambition to maintain a standard reactor design with minimal design changes from country to country.

“As all our organisations are reviewing essentially the same design in parallel, ONR is committed to exploring all opportunities for more efficient regulation, the sharing of insights and information, considering common submissions and analysis, and enabling GE-Hitachi to maintain a common design as much as possible.”

Saffron Price-Finnerty, the Environment Agency’s New Reactors Programme Manager, said: “Our Environment Agency team has been working diligently with GE-Hitachi to achieve the first major milestone of the GDA of its BWRX-300 small modular reactor design and we’re now ready to move from Step 1, Initiation, to Step 2, Fundamental Assessment.

“During Step 2, our skilled and experienced team will be assessing the underpinning fundamentals of the BWRX-300, including identifying any specific environmental protection issues, or concerns that we find.

“I’m grateful for the hard work of our team and that of GE-Hitachi to meet this milestone. We welcome GE-Hitachi’s initiative of taking a truly international approach in working towards a single design for global deployment. We’ll work with other regulators to see what can be achieved while ensuring protection of people and the environment.”

Natural Resources Wales participates in a GDA when the company designing the nuclear power station advises that its design might be proposed for construction in Wales.

Paul Gibson, Natural Resources Wales’ Radioactivity & Industry Policy Team Leader said: “As the project progresses to Step 2 (Fundamental Assessment), we will continue working closely with our regulatory partners, the Environment Agency and the Office for Nuclear Regulation, on the Generic Design Assessment of the GE-Hitachi BWRX-300.”

GE-Hitachi has launched a new GDA website to mark the beginning of Step 2. The website contains detailed information about their reactor design and features a public comments process.

This platform enables anyone  to submit comments and questions about the reactor design directly to the company for its response.

The regulators will consider any relevant issues raised during the comments process, along with GE-Hitachi’s responses to these issues, to help inform their ongoing assessment throughout the remainder of the GDA process.

This GDA is being managed in the UK by GE-Hitachi Nuclear Energy International LLC (UK Branch) which is the Requesting Party (RP). GE Vernova Inc is the ultimate parent company of GE-Hitachi Nuclear Energy International LLC overseeing the design of the reactor.

GE-Hitachi is receiving some of its funding for its own costs, and those of the regulators, for this GDA from the government’s Future Nuclear Enabling Fund programme.

Separately, GE-Hitachi has been selected by Great British Nuclear to advance to the next phase of the small modular reactor competition to identify technologies to be included in the UK nuclear programme.

GE-Hitachi applied for a two-step GDA which is expected to complete in December 2025. At the end of Step 2, the regulators will publish Step 2 GDA Statements indicating their level of confidence in whether the design can potentially be built, operated, and decommissioned in Great Britain in a way that is safe, secure and protects the environment.

No Design Acceptance Confirmation (DAC) or Statement of Design Acceptability (SoDA) will be issued at the end of the currently agreed programme of work.

Should an organisation wish to bring forward plans to deploy GE-Hitachi’s BWRX-300 in Great Britain, a further period of detailed design assessment will need to be carried out by the regulators before safety significant construction can commence and environmental permits are issued. 

This could be undertaken on a generic basis with GE-Hitachi if it chooses to return to GDA to complete Step 3, or it could be done with a UK licensee/constructor as part of a site-specific development.

For more information, please read ONR’s end of Step 1 statement and the Environment Agency and Natural Resources Wales (NRW) joint end of Step 1 statement.

You can also visit the GE-Hitachi GDA website.